debate, i don't think there's any doubt that congressman ryan and i, governor romney and the president, we have a fundamentally different vision for america. and quite frankly a fundamentally different value set. >> woodruff: democrats had been down after president obama's performance last week, but the vice-president aggressively challenged every point ryan made, prompting this exchange. >> mr. vice president, i know you're under a lot of duress... >> ( laughs ) >> ...to make up for lost ground, but i think people would be better served if we don't keep interrupting each other. >> well, don't take all the four minutes, then. >> woodruff: the president was quick to hail that performance immediately after the debate. >> i thought joe biden was terrific tonight. i could not be prouder of him. i thought he made a very strong case. >> woodruff: republican ryan sounded upbeat about how he'd done at a diner this morning before leaving lexington, kentucky. >> i felt great about it. >> reporter: did you feel knocked around by him? >> no, it's what i expected. >> woodruff: and mitt romney prais